[Xen-devel,v2,10/15] xen/passthrough: iommu: Basic support of device tree assignment

Message ID 1393193792-20008-11-git-send-email-julien.grall@linaro.org
State Superseded
Headers show

Commit Message

Julien Grall Feb. 23, 2014, 10:16 p.m.
Add IOMMU helpers to support device tree assignment/deassignment. This patch
introduces 2 new fields in the dt_device_node:
    - is_protected: Does the device is protected by an IOMMU
    - next_assigned: Pointer to the next device assigned to the same
    domain

Signed-off-by: Julien Grall <julien.grall@linaro.org>

---
    Changes in v2:
        - Patch added
---
 xen/common/device_tree.c              |    4 ++
 xen/drivers/passthrough/Makefile      |    1 +
 xen/drivers/passthrough/device_tree.c |  106 +++++++++++++++++++++++++++++++++
 xen/drivers/passthrough/iommu.c       |   10 ++++
 xen/include/xen/device_tree.h         |   14 +++++
 xen/include/xen/hvm/iommu.h           |    6 ++
 xen/include/xen/iommu.h               |   16 +++++
 7 files changed, 157 insertions(+)
 create mode 100644 xen/drivers/passthrough/device_tree.c

Comments

Julien Grall Feb. 24, 2014, 1:07 p.m. | #1
Hi Jan,

On 02/24/2014 10:47 AM, Jan Beulich wrote:
>>>> On 23.02.14 at 23:16, Julien Grall <julien.grall@linaro.org> wrote:
>> Add IOMMU helpers to support device tree assignment/deassignment. This patch
>> introduces 2 new fields in the dt_device_node:
>>     - is_protected: Does the device is protected by an IOMMU
>>     - next_assigned: Pointer to the next device assigned to the same
>>     domain
>>
>> Signed-off-by: Julien Grall <julien.grall@linaro.org>
>>
>> ---
>>     Changes in v2:
>>         - Patch added
>> ---
>>  xen/common/device_tree.c              |    4 ++
>>  xen/drivers/passthrough/Makefile      |    1 +
>>  xen/drivers/passthrough/device_tree.c |  106 +++++++++++++++++++++++++++++++++
>>  xen/drivers/passthrough/iommu.c       |   10 ++++
>>  xen/include/xen/device_tree.h         |   14 +++++
>>  xen/include/xen/hvm/iommu.h           |    6 ++
>>  xen/include/xen/iommu.h               |   16 +++++
> 
> No matter how small the changes to generic IOMMU code, you should
> Cc the maintainers.

Oops, sorry.

>> --- a/xen/drivers/passthrough/iommu.c
>> +++ b/xen/drivers/passthrough/iommu.c
>> @@ -123,6 +123,12 @@ int iommu_domain_init(struct domain *d)
>>      if ( ret )
>>          return ret;
>>  
>> +#if HAS_DEVICE_TREE
>> +    ret = iommu_dt_domain_init(d);
>> +    if ( ret )
>> +        return ret;
>> +#endif
> 
> Why can this not be part of arch_iommu_domain_init()?

I didn't think about this solution. I will move in
arch_iommu_domain_init in the next version.

>> @@ -198,6 +204,10 @@ void iommu_domain_destroy(struct domain *d)
>>      if ( need_iommu(d) )
>>          iommu_teardown(d);
>>  
>> +#ifdef HAS_DEVICE_TREE
>> +    iommu_dt_domain_destroy(d);
>> +#endif
>> +
>>      arch_iommu_domain_destroy(d);
> 
> And the former one here part of the latter?

Ok.

>> @@ -28,6 +29,11 @@ struct hvm_iommu {
>>  
>>      /* iommu_ops */
>>      const struct iommu_ops *platform_ops;
>> +
>> +    #ifdef HAS_DEVICE_TREE
>> +    /* List of DT devices assigned to this domain */
>> +    struct list_head dt_devices;
>> +    #endif
> 
> Indentation.

Will do.

Cheers,

Patch

diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
index 564f2bb..7c6b683 100644
--- a/xen/common/device_tree.c
+++ b/xen/common/device_tree.c
@@ -1695,6 +1695,10 @@  static unsigned long __init unflatten_dt_node(const void *fdt,
         np->full_name = ((char *)np) + sizeof(struct dt_device_node);
         /* By default dom0 owns the device */
         np->used_by = 0;
+        /* By default the device is not protected */
+        np->is_protected = false;
+        INIT_LIST_HEAD(&np->next_assigned);
+
         if ( new_format )
         {
             char *fn = np->full_name;
diff --git a/xen/drivers/passthrough/Makefile b/xen/drivers/passthrough/Makefile
index 6e08f89..5a0a35e 100644
--- a/xen/drivers/passthrough/Makefile
+++ b/xen/drivers/passthrough/Makefile
@@ -5,3 +5,4 @@  subdir-$(x86_64) += x86
 obj-y += iommu.o
 obj-$(x86) += io.o
 obj-$(HAS_PCI) += pci.o
+obj-$(HAS_DEVICE_TREE) += device_tree.o
diff --git a/xen/drivers/passthrough/device_tree.c b/xen/drivers/passthrough/device_tree.c
new file mode 100644
index 0000000..7384e73
--- /dev/null
+++ b/xen/drivers/passthrough/device_tree.c
@@ -0,0 +1,106 @@ 
+/*
+ * xen/drivers/passthrough/arm/device_tree.c
+ *
+ * Code to passthrough device tree node to a guest
+ *
+ * Julien Grall <julien.grall@linaro.org>
+ * Copyright (c) 2014 Linaro Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <xen/lib.h>
+#include <xen/sched.h>
+#include <xen/iommu.h>
+#include <xen/device_tree.h>
+
+static spinlock_t dtdevs_lock = SPIN_LOCK_UNLOCKED;
+
+int iommu_assign_dt_device(struct domain *d, struct dt_device_node *dev)
+{
+    int rc = -EBUSY;
+    struct hvm_iommu *hd = domain_hvm_iommu(d);
+
+    if ( !iommu_enabled || !hd->platform_ops )
+        return -EINVAL;
+
+    if ( !dt_device_is_protected(dev) )
+        return -EINVAL;
+
+    spin_lock(&dtdevs_lock);
+
+    if ( !list_empty(&dev->next_assigned) )
+        goto fail;
+
+    rc = hd->platform_ops->assign_dt_device(d, dev);
+
+    if ( rc )
+        goto fail;
+
+    list_add(&dev->next_assigned, &hd->dt_devices);
+    dt_device_set_used_by(dev, d->domain_id);
+
+fail:
+    spin_unlock(&dtdevs_lock);
+
+    return rc;
+}
+
+int iommu_deassign_dt_device(struct domain *d, struct dt_device_node *dev)
+{
+    struct hvm_iommu *hd = domain_hvm_iommu(d);
+    int rc;
+
+    if ( !iommu_enabled || !hd->platform_ops )
+        return -EINVAL;
+
+    if ( !dt_device_is_protected(dev) )
+        return -EINVAL;
+
+    spin_lock(&dtdevs_lock);
+
+    rc = hd->platform_ops->reassign_dt_device(d, dom0, dev);
+    if ( rc )
+        goto fail;
+
+    dt_device_set_used_by(dev, dom0->domain_id);
+
+    list_del(&dev->next_assigned);
+
+fail:
+    spin_unlock(&dtdevs_lock);
+
+    return rc;
+}
+
+int iommu_dt_domain_init(struct domain *d)
+{
+    struct hvm_iommu *hd = domain_hvm_iommu(d);
+
+    INIT_LIST_HEAD(&hd->dt_devices);
+
+    return 0;
+}
+
+void iommu_dt_domain_destroy(struct domain *d)
+{
+    struct hvm_iommu *hd = domain_hvm_iommu(d);
+    struct dt_device_node *dev, *_dev;
+    int rc;
+
+    list_for_each_entry_safe(dev, _dev, &hd->dt_devices, next_assigned)
+    {
+        rc = iommu_deassign_dt_device(d, dev);
+        if ( rc )
+            dprintk(XENLOG_ERR, "Failed to deassign %s in domain %u\n",
+                    dt_node_full_name(dev), d->domain_id);
+    }
+}
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index e6a1839..6c951d0 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -123,6 +123,12 @@  int iommu_domain_init(struct domain *d)
     if ( ret )
         return ret;
 
+#if HAS_DEVICE_TREE
+    ret = iommu_dt_domain_init(d);
+    if ( ret )
+        return ret;
+#endif
+
     if ( !iommu_enabled )
         return 0;
 
@@ -198,6 +204,10 @@  void iommu_domain_destroy(struct domain *d)
     if ( need_iommu(d) )
         iommu_teardown(d);
 
+#ifdef HAS_DEVICE_TREE
+    iommu_dt_domain_destroy(d);
+#endif
+
     arch_iommu_domain_destroy(d);
  }
 
diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h
index d429e60..2aae047 100644
--- a/xen/include/xen/device_tree.h
+++ b/xen/include/xen/device_tree.h
@@ -16,6 +16,7 @@ 
 #include <xen/string.h>
 #include <xen/types.h>
 #include <xen/stdbool.h>
+#include <xen/list.h>
 
 #define DEVICE_TREE_MAX_DEPTH 16
 
@@ -110,6 +111,9 @@  struct dt_device_node {
     struct dt_device_node *next; /* TODO: Remove it. Only use to know the last children */
     struct dt_device_node *allnext;
 
+    /* IOMMU specific fields */
+    bool is_protected; /* Tell if the device is protected by an IOMMU */
+    struct list_head next_assigned;
 };
 
 #define MAX_PHANDLE_ARGS 16
@@ -325,6 +329,16 @@  static inline domid_t dt_device_used_by(const struct dt_device_node *device)
     return device->used_by;
 }
 
+static inline void dt_device_set_protected(struct dt_device_node *device)
+{
+    device->is_protected = true;
+}
+
+static inline bool dt_device_is_protected(const struct dt_device_node *device)
+{
+    return device->is_protected;
+}
+
 static inline bool_t dt_property_name_is_equal(const struct dt_property *pp,
                                                const char *name)
 {
diff --git a/xen/include/xen/hvm/iommu.h b/xen/include/xen/hvm/iommu.h
index f8f8a93..72002e1 100644
--- a/xen/include/xen/hvm/iommu.h
+++ b/xen/include/xen/hvm/iommu.h
@@ -21,6 +21,7 @@ 
 #define __XEN_HVM_IOMMU_H__
 
 #include <xen/iommu.h>
+#include <xen/list.h>
 #include <asm/hvm/iommu.h>
 
 struct hvm_iommu {
@@ -28,6 +29,11 @@  struct hvm_iommu {
 
     /* iommu_ops */
     const struct iommu_ops *platform_ops;
+
+    #ifdef HAS_DEVICE_TREE
+    /* List of DT devices assigned to this domain */
+    struct list_head dt_devices;
+    #endif
 };
 
 #endif /* __XEN_HVM_IOMMU_H__ */
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 5a19c80..266cd6e 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -82,6 +82,16 @@  bool_t pt_irq_need_timer(uint32_t flags);
 #define PT_IRQ_TIME_OUT MILLISECS(8)
 #endif /* HAS_PCI */
 
+#ifdef HAS_DEVICE_TREE
+#include <xen/device_tree.h>
+
+int iommu_assign_dt_device(struct domain *d, struct dt_device_node *dev);
+int iommu_deassign_dt_device(struct domain *d, struct dt_device_node *dev);
+int iommu_dt_domain_init(struct domain *d);
+void iommu_dt_domain_destroy(struct domain *d);
+
+#endif /* HAS_DEVICE_TREE */
+
 #ifdef CONFIG_X86
 struct msi_desc;
 struct msi_msg;
@@ -101,6 +111,12 @@  struct iommu_ops {
 			   u8 devfn, struct pci_dev *);
     int (*get_device_group_id)(u16 seg, u8 bus, u8 devfn);
 #endif /* HAS_PCI */
+#ifdef HAS_DEVICE_TREE
+    int (*assign_dt_device)(struct domain *d, const struct dt_device_node *dev);
+    int (*reassign_dt_device)(struct domain *s, struct domain *t,
+                              const struct dt_device_node *dev);
+#endif
+
     void (*teardown)(struct domain *d);
     int (*map_page)(struct domain *d, unsigned long gfn, unsigned long mfn,
                     unsigned int flags);